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State identification of home appliance with transient features in residential buildings

《能源前沿（英文）》 2022年第16卷第1期页码 130-143 doi: 10.1007/s11708-022-0822-z

摘要： Nonintrusive load monitoring (NILM) is crucial for extracting patterns of electricity consumption of household appliance that can guide users’ behavior in using electricity while their privacy is respected. This study proposes an online method based on the transient behavior of individual appliances as well as system steady-state characteristics to estimate the operating states of the appliances. It determines the number of states for each appliance using the density-based spatial clustering of applications with noise (DBSCAN) method and models the transition relationship among different states. The states of the working appliances are identified from aggregated power signals using the Kalman filtering method in the factorial hidden Markov model (FHMM). Thereafter, the identified states are confirmed by the verification of system states, which are the combination of the working states of individual appliances. The verification step involves comparing the total measured power consumption with the total estimated power consumption. The use of transient features can achieve fast state inference and it is suitable for online load disaggregation. The proposed method was tested on a high-resolution data set such as Labeled hIgh-Frequency daTaset for Electricity Disaggregation (LIFTED) and it outperformed other related methods in the literature.

关键词： nonintrusive load monitoring (NILM) load disaggregation online load disaggregation Kalman filtering factorial hidden Markov model (FHMM) Labeled hIgh-Frequency daTaset for Electricity Disaggregation (LIFTED)

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Image-based fall detection and classification of a user with a walking support system

Sajjad TAGHVAEI, Kazuhiro KOSUGE

《机械工程前沿（英文）》 2018年第13卷第3期页码 427-441 doi: 10.1007/s11465-017-0465-7

摘要：

The classification of visual human action is important in the development of systems that interact with humans. This study investigates an image-based classification of the human state while using a walking support system to improve the safety and dependability of these systems. We categorize the possible human behavior while utilizing a walker robot into eight states (i.e., sitting, standing, walking, and five falling types), and propose two different methods, namely, normal distribution and hidden Markov models (HMMs), to detect and recognize these states. The visual feature for the state classification is the centroid position of the upper body, which is extracted from the user’s depth images. The first method shows that the centroid position follows a normal distribution while walking, which can be adopted to detect any non-walking state. The second method implements HMMs to detect and recognize these states. We then measure and compare the performance of both methods. The classification results are employed to control the motion of a passive-type walker (called “RT Walker”) by activating its brakes in non-walking states. Thus, the system can be used for sit/stand support and fall prevention. The experiments are performed with four subjects, including an experienced physiotherapist. Results show that the algorithm can be adapted to the new user’s motion pattern within 40 s, with a fall detection rate of 96.25% and state classification rate of 81.0%. The proposed method can be implemented to other abnormality detection/classification applications that employ depth image-sensing devices.

关键词： fall detection walking support hidden Markov model multivariate analysis

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多带同步模型用于噪声环境下语音识别

孙暐,吴镇扬

《中国工程科学》 2006年第8卷第3期页码 31-34

摘要：

根据人耳听觉特性，提出新的同步多带最大似然线性回归算法用于噪声环境下语音识别。该算法采用最大似然作为参数估计准则，利用各频带信号同步感知和噪声污染假定的方法进行语音模型补偿，有效地提高了识别系统在噪声环境下的识别性能。

关键词：隐马尔可夫模型最大似然多带同步模型语音识别

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TPE-H2MWD: 基于隐马尔科夫模型和分权扩散的精确缩略图保留加密方案 Research Article

柴秀丽1,2,陈绣辉1,马亚坤1,左方3,甘志华2,3,张玉书4

《信息与电子工程前沿（英文）》 2023年第24卷第8期页码 1169-1180 doi: 10.1631/FITEE.2200498

摘要：随着图像传输技术日益发展，人们对图像安全的需求也在大幅提升。由传统图像加密方案获得的类噪声图像虽然可以保证内容安全，但无法直接用于预览和检索。一些学者基于排序后加密方法，设计了一种三像素缩略图保留加密方案（TPE2），用于平衡图像安全性和可用性，然而该方案的加密效率较低。为此，本文提出一种有效的精确缩略图保留加密方案。首先对明文图像进行分块和位平面置乱，然后采用Z字形置乱模型改变最低的4个位平面中比特的位置，随后介绍了用于改变最高的4个位平面中比特位置的操作（这是隐马尔科夫模型的一个扩展应用）。最后，根据每个位平面中比特的权重不同，设计了一种比特级分权扩散规则。至此生成的加密图像能保证块内像素和不变。仿真结果表明，该方案在平衡图像隐私性和可用性的同时，提高了加密效率。

关键词：隐马尔科夫模型；分权扩散；可用性与隐私性之间的平衡；图像加密

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Identification of pollution sources in rivers using a hydrodynamic diffusion wave model and improvedBayesian-Markov chain Monte Carlo algorithm

《环境科学与工程前沿（英文）》 2023年第17卷第7期 doi: 10.1007/s11783-023-1685-1

摘要：

● A hydrodynamic-Bayesian inference model was developed for water pollution tracking.

关键词： Identification of pollution sources Water quality restoration Bayesian inference Hydrodynamic model Inverse problem

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火灾事故的灰色-马尔可夫模型预测研究

毛占利,朱毅,杨伯忠,朱磊

《中国工程科学》 2010年第12卷第1期页码 98-101

摘要：

鉴于火灾事故的发生受多种复杂因素的影响，并且具有较大的随机性和波动性的特点，笔者等将灰色模型和马尔可夫模型相结合，建立火灾事故的灰色–马尔可夫模型，利用灰色模型的灰色性和马尔可夫模型的随机性来体现各自的优点，并运用该模型对全国农村火灾事故进行预测。实际应用表明，灰色–马尔可夫模型的预测精度明显高于灰色模型的预测精度，完全能满足预测精度的要求，可以较好地用于火灾事故的预测。

关键词：灰色模型马尔可夫模型火灾事故预测

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马尔可夫网络排队模型在电梯配置中的应用

宗群,程义菊,宋军远

《中国工程科学》 2003年第5卷第10期页码 69-72

摘要：

利用马尔可夫网络排队理论建立了电梯交通模型，在此基础上对各服务站的电梯配置交通进行计算，得到电梯的配置参数。通过与传统的电梯配置方法相比较，显示出明显的优越性，也表明了利用马尔可夫网络排队模型进行电梯配置的有效性和可行性。

关键词：马尔可夫网络排队理论电梯交通模型优化电梯配置

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融合深度置信网络的串联隐马尔科夫模型及其在脱机手写识别中的应用 Article

Partha Pratim ROY, Guoqiang ZHONG, Mohamed CHERIET

《信息与电子工程前沿（英文）》 2017年第18卷第7期页码 978-988 doi: 10.1631/FITEE.1600996

摘要：在文档分析和模式识别领域，自由书写的脱机手写识别是一个非常具有挑战性的研究课题。近年来，为了充分探索隐藏在文档图像中的监督信息，许多研究工作试图将多层感知机以一种混合或串联的形式嵌入隐马尔科夫模型当中。然而，因为多层感知机学习能力的不足，学习到的特征对于后续的识别任务不一定是最优的。在本文中，我们针对自由书写的脱机手写识别提出一种基于深度结构的串联方法。在提出的模型中，深度置信网络被用于学习序列数据的紧致表示，隐马尔科夫模型被用于（子-）词的识别。我们在两个公开的数据集上验证了所提出的模型，这两个数据集是分别基于拉丁和阿拉伯语的RIMES和IFN/ENIT；我们还在Devanagari数据集上验证了所提出的模型，这个数据集是基于印度语的。大量的实验展示了所提出模型的优势，特别是相对于多层感知机-隐马尔科夫模型的串联方法。

关键词：手写识别；隐马尔科夫模型；深度学习；深度置信网络；串联方法

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基于广义极值分布和马尔科夫随机场的全极化合成孔径雷达图像潮间带区域地物分类方法 None

Ting-ting JIN, Xiao-qiang SHE, Xiao-lan QIU, Bin LEI

《信息与电子工程前沿（英文）》 2019年第20卷第2期页码 253-264 doi: 10.1631/FITEE.1700462

摘要：考虑到潮汐波动的复杂性和剧烈性，合成孔径雷达（SAR）图像的潮间带区域地物分类是一个重要且具有挑战性的问题。潮间带区域地物分类难点在于，潮间带有很大比例区域经常被海水淹没，使得利用空间信息的统计建模方法常常失效。考虑到极化熵和各向异性在潮间带特征描述中的重要作用，提出一种新的无监督地物分类算法。该算法将广义极值分布模型（GEV）的极化特征与马尔可夫随机场（MRF）的平滑滤波结合，并加入拟合优度检验，以确定统计模型各组成部分的显著性。将极化熵和各向异性的分类结果有效结合，得到最终分类结果。最后，基于中国高分三号SAR卫星获得的全极化数据进行实验，实验结果证明所提方法的可行性和优越性。

关键词：潮间带区域地物分类；极化合成孔径雷达；有限混合模型；马尔可夫随机场；广义极值分布模型

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Reliability evaluation of future photovoltaic systems with smart operation strategy

Amir AHADI,Hosein HAYATI,Seyed Mohsen MIRYOUSEFI AVAL

《能源前沿（英文）》 2016年第10卷第2期页码 125-135 doi: 10.1007/s11708-015-0392-4

摘要： This paper investigates a new operation strategy for photovoltaic (PV) systems, which improves the overall reliability of the system as a result of the improvement in the reliability of the critical components. First, a mathematical model is proposed using the fault tree analysis (FTA) to estimate the reliability of the PV systems in order to find the suitable maintenance strategies. The implementations demonstrate that it is essential to employ smart maintenance plans and monitor the identified most critical components of PV systems. Then, an innovative analytical method based on the Markov process is presented to model smart operation plans in PV systems. The impact of smart operation strategy on the PV systems is then evaluated. The objective of this paper is to develop plans for improving the reliability of PV systems. A series of case studies have been conducted to demonstrate the importance of smart operation strategies for PV systems as well as the applicability and feasibility of the proposed method.

关键词： smart operation strategy renewable energy fault tree analysis (FTA) Markov model

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Recent advances in “universal” influenza virus antibodies: the rise of a hidden trimeric interface in

Yulu Wang, Dan Hu, Yanling Wu, Tianlei Ying

《医学前沿（英文）》 2020年第14卷第2期页码 149-159 doi: 10.1007/s11684-020-0764-y

摘要： Influenza causes seasonal outbreaks yearly and unpredictable pandemics with high morbidity and mortality rates. Despite significant efforts to address influenza, it remains a major threat to human public health. This issue is partially due to the lack of antiviral drugs with potent antiviral activity and broad reactivity against all influenza virus strains and the rapid emergence of drug-resistant variants. Moreover, designing a universal influenza vaccine that is sufficiently immunogenic to induce universal antibodies is difficult. Some novel epitopes hidden in the hemagglutinin (HA) trimeric interface have been discovered recently, and a number of antibodies targeting these epitopes have been found to be capable of neutralizing a broad range of influenza isolates. These findings may have important implications for the development of universal influenza vaccines and antiviral drugs. In this review, we focused on the antibodies targeting these newly discovered epitopes in the HA domain of the influenza virus to promote the development of universal anti-influenza antibodies or vaccines and extend the discovery to other viruses with similar conformational changes in envelope proteins.

关键词： influenza virus neutralizing antibody hemagglutinin globular head region trimeric interface

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Research on pedestrian escape route without visibility based on Markov chain model

Xiaoping ZHENG, Lijuan DU, Hongjiang WANG,

《化学科学与工程前沿（英文）》 2010年第4卷第3期页码 283-289 doi: 10.1007/s11705-009-0272-8

摘要： It is a pioneering work to use a Markov chain model to study the pedestrian escape route without visibility. In this paper, based on the Markov chain probability transition matrix, the algorithms with random numbers and the spatial-grid, an escape route in a limited invisible space is obtained. Six pace states (standing, crawling, walking, leaping, jogging, and running) are applied to describe the characteristics of pedestrian behaviors. Besides, eight main direction changes are used to describe the transition characteristic of a pedestrian. At the same time, this paper analyzes the escape route from two views, i.e., pedestrian pace states and directions. The research results show that the Markov chain model is more realistic as a means of studying pedestrian escape routes.

关键词： pioneering direction spatial-grid realistic transition characteristic

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A new method for estimating the longevity and degradation of photovoltaic systems considering weather states

Amir AHADI,Hosein HAYATI,Joydeep MITRA,Reza ABBASI-ASL,Kehinde AWODELE

《能源前沿（英文）》 2016年第10卷第3期页码 277-285 doi: 10.1007/s11708-016-0400-3

摘要： The power output of solar photovoltaic (PV) systems is affected by solar radiation and ambient temperature. The commonly used evaluation techniques usually overlook the four weather states which are clear, cloudy, foggy, and rainy. In this paper, an ovel analytical model of the four weather conditions based on the Markov chain is proposed. The Markov method is well suited to estimate the reliability and availability of systems based on a continuous stochastic process. The proposed method is generic enough to be applied to reliability evaluation of PV systems and even other applications. Further aspects investigated include the new degradation model for reliability predication of PV modules. The results indicate that the PV module degradation over years, failures, and solar radiation must be considered in choosing an efficient PV system with an optimal design to achieve the maximum benefit of the PV system. For each aspect, a method is proposed, and the complete focusing methodology is expounded and validated using simulated point targets. The results also demonstrate the feasibility and applicability of the proposed method for effective modeling of the chronological aspects and stochastic characteristics of solar cells as well as the optimal configuration and sizing of large PV plants in terms of cost and reliability.

关键词： photovoltaic (PV) systems solar cell Markov model weather effects

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Sequential degradation-based burn-in test with multiple periodic inspections

《工程管理前沿（英文）》 2021年第8卷第4期页码 519-530 doi: 10.1007/s42524-021-0166-0

摘要： Burn-in has been proven effective in identifying and removing defective products before they are delivered to customers. Most existing burn-in models adopt a one-shot scheme, which may not be sufficient enough for identification. Borrowing the idea from sequential inspections for remaining useful life prediction and accelerated lifetime test, this study proposes a sequential degradation-based burn-in model with multiple periodic inspections. At each inspection epoch, the posterior probability that a product belongs to a normal one is updated with the inspected degradation level. Based on the degradation level and the updated posterior probability, a product can be disposed, put into field use, or kept in the test till the next inspection epoch. We cast the problem into a partially observed Markov decision process to minimize the expected total burn-in cost of a product, and derive some interesting structures of the optimal policy. Then, algorithms are provided to find the joint optimal inspection period and number of inspections in steps. A numerical study is also provided to illustrate the effectiveness of our proposed model.

关键词： burn-in degradation multiple inspections Wiener process partially observed Markov decision process

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Enhanced production of laccase by

Wei SUN, Meiying XU, Chunyu XIA, Anhua LI, Guoping SUN

《环境科学与工程前沿（英文）》 2013年第7卷第2期页码 200-210 doi: 10.1007/s11783-012-0457-0

摘要： The effect of physical parameters of cultivation (load volume, temperature, pH, agitation, inoculum size, and incubation period) in the production of laccase by wood-rotting basidiomycete were studied using diluted molasses distillery wastewater (MDW) as a major composition. Using fractional factorial design, our study first identified load volume, agitation, and inoculum size as statistically significant factors. Optimal preferences and mutual interactions of the factors were then determined by the response surface method, which is based on the center composite design. A quadratic model was used to fit the experimental data. The optimized operational parameters for laccase production were determined to be the following: culture temperature of 25°C, pH 4, load volume of 40 mL diluted MDW in 150 mL flask, agitation rate of 183 r·min , inoculation of 11.5% v/v, and cultivation time of 6 d. The experimental validation under these conditions (the maximum laccase production of 2198.2 U·mL was within the confidence interval) subsequently verified the accuracy of the constructed model. Moreover, the removal of chemical oxygen demand and nitrogen of MDW reached 62.85% and 48.00% respectively, and the decolorization ratio under the optimal condition was 41.85%. The enhanced production of laccase by is a new recovery strategy for MDW.

关键词： laccase Coriolus hirsutus fractional factorial design response surface method molasses distillery wastewater